Hi Andrzej, thanks for the hint. I'll try to code that in DemDisplay today. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Andrzej Popowski <popej@poczta.onet.pl> Gesendet: Freitag, 12. Januar 2018 13:10:32 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] option --show-profiles and DEM Hi Nick, DEM in GMP should be the same. The difference is, that in DEM subfile headers starts at 0, but in GMP header is at address contained at offset 0x2D. If you want to analyze DEM then algorithm is something like that: char *subfile int offset; if (typ == DEM) offset = 0 if (typ == GMP) offset = *(int *)(subfile + 0x2D); HEADER_DEM *header = (HEADER_DEM *)(subfile + offset) And then you can access DEM data basing on header content. Pointers in header are correct regardless of header position inside subfile, they are always relative to beginning of subfile. -- Best regards, Andrzej _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev